The subject invention relates to a system for recharging postage meters. More particularly, it relates to a system for automatically recharging a postage meter with funds to allow the meter to continue operation.
Postage meters are devices which have found wide application in many business. Such meters are used to frank parcels and mail by printing indicia which are equivalent to postage stamps. Clearly, it is therefor essential that postage meters include a secure mechanism to assure that the meter prints only postage for which the postal service has been paid. Equally clearly, the secure mechanism must allow the postage meter to be reset or recharged with additional funds. That is, a mechanism must be provided which will allow the postage meter to print additional postage if and only if an equivalent amount has been paid to the postal service.
(Those skilled in the art will recognize that other forms of valve, e.g. tax stamps, may be dispensed by postage meter-like devices. As used herein the term "postage meter" contemplates such devices which include secure, rechargeable mechanisms for controlled dispensing of value.)
Various schemes have been devised and implemented to obtain the desired remote recharging based on information from a remote data processing center. Typical systems are shown in U.S. Pat. No.: 3,792,446, to McFiggans et al., entitled REMOTE POSTAGE METER RESETTING METHOD; and in U.S. Pat. No. 4,097,923, to Eckert, Jr. et al. , entitled POSTAGE METER CHARGING SYSTEM USING AN ADVANCED MICROCOMPUTERIZED POSTAGE METER. These patents teach a data processing center which is equipped with a programmed digital computer and a voice answer-back unit to process telephone calls from users of postage meters equipped with either a combination lock such that the lock prohibits recharging of the associated meter until it is unlocked, or, in the case of U.S. Pat. No. 4,097,923, having a working memory which contains a seed number for generating postage funding combinations to unlock the meter. The remote system of the later patent includes the capability of adding variable amounts of postage to the postage meter. U.S. Pat. No. 3,792,446, relates only to the addition of fixed increments to the meter. Each of these systems is based on transmission by a postage meter user of information including, or derived from, the contents of the meter ascending and descending registers, the meter serial number, an account number to be debited for the amount of funds to be recharged, and in the case of a variable recharge system, the amount by which the meter is to be recharged. If the data processing center includes a voice answer-back system, the operator may transmit the information using DTMF tones over the telephone system or the operator may simply speak to a second operator at the data processing center to transmit the information. In either case the data processing center then provides an encrypted number which may be used to recharge the meter, as is described in the above referenced patents.
As is well know to those skilled in the art the ascending register of a postage meter is a large capacity register which is incremented by the postage amount each time the meter prints an indicia, and thus contains the total amount of postage printed by the meter over its lifetime. The descending register is decremented by the amount of postage each time an indicia is printed and incremented by the amount of funds each time the meter is recharged. The meter, of course, cannot print postage in excess of the amount of funds in the descending register. The total of the ascending and the descending register is equal to the total amount of funds with which the meter has been charged in its lifetime. (Sometimes herein referred to as the control sum.) Since the recharge code is generated using a secure algorithm and is based on information which includes the control sum and the serial number of the meter, it is apparent that each recharge of the meter will require a secure, unique recharge code.
Such recharging systems are marketed by Pitney Bowes Inc., the assignee of the subject application, under the trademark "Postage-by-Phone", and are described more fully in the above referenced patents.
In the systems described above the recharge code is entered into a postage meter, such as the Pitney Bowes Model 6900 Electronic Meter, manually through a key pad by an operator. Alternately, the information may be entered into the Model 6900 Meter through a communications port which is normally used for communication with a postal scale using a proprietary Pitney Bowes communications protocol described in U.S. Pat. No. 4,498,187; to Soderberg et al.
U.S. Pat. No. 3,255,493 to Simjian discloses a system in which the meter communicates directly to a central accounting station for accounting for each and all of the meter operations, either on a real time basis or in batches. A similar system is disclosed in West German Patent Application No.: DE 2,636,852, published Feb. 23, 1978; in which a data transmitting unit is employed to recharge the postage meter over telephone or telegraph lines. British Patent Application No.: 2,147,853, published May 22, 1985, discloses a telephone integrated with a mail franking device, which operates either as a telephone or as a postage meter. The telephone key pad may be used to recharge funds and accounting may be done either locally at the device or in a central accounting unit.
Each of the above described devices requires a complex sequence of operations to recharge a postage meter. U.S. Pat. No. 4,812,992 to Storace et al., issued Mar. 14, 1989, discloses a system which attempts to simplify the recharging process. In Patent No. 4,812,992, a novel postage meter which includes a dedicated communications port, which is preferably a DTMF transmitter/receiver for telephone communications, is connected over the telephone network to a remote data processing center, such as a Pitney Bowes "Postage-by-Phone" center. Each meter has the capability to initiate and complete a recharging transaction with the data processing center whenever its funds (i.e., the contents of its descending register) fall below a preset limit.
While effective, the system of Patent No. 4,812,992, requires the design and implementation of an entire new meter design and the approval of that meter by the US Postal Service.
Thus it is an object of the subject invention to provide a system for simply and automatically recharging an electronic postage meter.
It is a further object of the subject invention to provide such a system which is compatible with existing postage meters without the necessity of obtaining approvals from a postal service.
Other objects and advantages of the subject invention will be apparent to those skilled in the art from consideration of the attached drawings and of the detailed description set forth below.